It is often necessary, for various reasons, to determine which circuit breaker in a circuit breaker box, controls the flow of current to a given electrical outlet. The process of determining which circuit breaker is associated with a given outlet is quite time consuming. For instance, many people simply take a lamp and plug it into the electrical outlet that they desire to check. They then walk to the circuit breaker box and open the first circuit breaker. They then walk back to the lamp and see if it is still illuminated. If the lamp is illuminated, the person knows that the first circuit breaker does not correspond to the electrical outlet where the lamp is plugged in. If the lamp is not illuminated, the person has identified the circuit breaker corresponding to that particular outlet where the lamp is plugged in. By using this method, a person must often make numerous trips between the circuit breaker box and the desired electrical outlet, consuming much time. A further disadvantage of this method is its obvious shortcomings in a hospital setting, for instance where artificial respirators are used.
To overcome these disadvantages, the prior art developed a line tester comprising a receiver and a transmitter. An example of such a line tester is disclosed in U.S. Pat. No. 4,642,556. Essentially, the line tester has a receiver and a transmitter. The transmitter is plugged into the electrical outlet the operator desires to check. The transmitter sends current pulses along the electrical conductor, the electrical conductor terminating at the circuit breaker box. The operator walks to the circuit breaker box and waves a wand-like receiver in close proximity to the circuit breaker box. The receiver has a sensing coil. The transmitter's current pulse generates a signal in the sensing coil when the receiver is close enough to the controlling circuit breaker of the desired electrical outlet. The signal is amplified and the receiver, via indicators, notifies the operator that the receiver is in close proximity to the circuit breaker corresponding to the electrical outlet where the transmitter is plugged in.
However, the above-described line testers have many disadvantages. First, the above-described units have been effective is sensing conductors in electrical connection with resistive loads or computer apparatus, but not both. Second, the operator must walk from the circuit breaker back to the old electrical outlet, then to a new electrical outlet and finally back to the circuit breaker box in order to test a second electrical outlet. If many electrical outlets need testing, this method is quite time consuming. Third, previous transmitters place a resistive load in series with the conductor. Therefore, due to power dissipation considerations, the transmitters do not continually transmit and instead transmit current pulses in pre-determined duty cycles.
Accordingly, it is a primary object of the present invention to provide a circuit breaker tester with multiple transmitters.
Another object of the present invention is to provide a circuit breaker tester whose transmitters can continuously transmit signature signals.
Yet another object of the present invention is to provide a device that functions effectively regardless of the load electrically connected to the conductor (e.g. the present device performs resistive-sensing and computer-sensing equally as well).